The subject invention pertains to a new shape charge for use in a perforating gun, and more particularly, to a new solid state detonator for use in each such shape charge.
Perforating guns of the prior art generally include a plurality of shape charges, each charge containing an explosive material. A detonating cord is traditionally connected to each shape charge for detonating the explosive material in each charge when a heat source ignites the detonating cord. However, the detonating cord could be ignited when radio-frequency (RF) energy nearby induces a current in an input circuit high enough to ignite the cord. Therefore, elaborate steps must be taken to ensure that RF energy does not inadvertently detonate the charges in the perforating gun. Such steps have thus far concentrated on utilization of sophisticated input circuits designed to create large current surges that ultimately ignite the detonating cord. Use of detonating cords creates a safety risk; thus, such detonating cords must be handled carefully to avoid accidents. Of course, when detonating cords are used, shape charges in the perforating gun must be detonated sequentially, since the charges cannot be detonated simultaneously. All of these considerations reflect the need for a new type of shape charge, one which is immune to RF energy, one which does not use detonating cords to reduce the safety risk, and one which allows all shape charges in the perforating gun to be detonated substantially simultaneously.